Out of ideas

It's that time of year, when the faint shadow of November stirs and reminds you, in a chill whisper, that you have NO IDEA what to write for your NaNoWriMo novel this year.  This will be my seventh year of NaNo'ing.

This is a problem I have two months to solve.  It's going to take at least two weeks to hammer out a plot, so I need this thing by October 15th.

Intarwebz, I need your help.

I need a plot, or an idea, or even elements of an idea, that can span a 50,000 word novel, which is about the length of The Great Gatsby, or The Hitch Hiker's Guide to the Galaxy.  I write sci-fi, or maybe fantasy, and I have a hard science/geek/tech background.  I cannot write chick lit to save my life, or anyone else's life.  Also I have trouble writing anything even remotely romantic.  I like explosions.

Please leave me a comment if you have a spare idea.  I promise that if it gets published, I'll put you in the credits.  If not, the idea and I will have one heck of a ride through November and I'll make sure it's wearing a seatbelt.  I'm not quite desperate enough to break out the ninjas, pirates, or dinosaurs.  What have you got?